add and pass all tests - Alexander Raffe Aleksanyan

src/arrays.js

@@ -8,34 +8,87 @@ const each = (elements, cb) => {
   // Iterates over a list of elements, yielding each in turn to the `cb` function.
   // This only needs to work with arrays.
   // based off http://underscorejs.org/#each
+  if (Array.isArray(elements)) {
+    for (let i = 0; i < elements.length; i++) {
+      cb(elements[i], i, elements);
+    }
+  } else if (elements === null) {
+    return elements;
+  }
 };
 
 const map = (elements, cb) => {
   // Produces a new array of values by mapping each value in list through a transformation function (iteratee).
   // Return the new array.
+  const result = [];
+
+  each(elements, (item) => {
+    result.push(cb(item));
+  });
+
+  return result;
 };
 
 const reduce = (elements, cb, memo = elements.shift()) => {
   // Combine all elements into a single value going from left to right.
   // Elements will be passed one by one into `cb`.
   // `memo` is the starting value.  If `memo` is undefined then make `elements[0]` the initial value.
+  let memoUndefined = arguments.length < 3;
+  each(elements, (element, index) => {
+    if (memoUndefined) {
+      memoUndefined = false;
+      memo = element;
+    } else {
+      return memo = cb(memo, element, index);
+    }
+  });
+
+  return memo;
 };
 
 const find = (elements, cb) => {
   // Look through each value in `elements` and pass each element to `cb`.
   // If `cb` returns `true` then return that element.
   // Return `undefined` if no elements pass the truth test.
+  const arr = [];
+
+  each(elements, (element, index) => {
+    if (cb(element, index)) {
+      arr.push(element);
+    }
+  });
+
+  if (arr.length === 0) {
+    return undefined;
+  }
+
+  return arr[0];
 };
 
 const filter = (elements, cb) => {
   // Similar to `find` but you will return an array of all elements that passed the truth test
   // Return an empty array if no elements pass the truth test
+  const arr = [];
+  each(elements, (element, index) => {
+    if (cb(element, index)) {
+      arr.push(element);
+    }
+  });
+
+  return arr;
 };
 
 /* Extra Credit */
 const flatten = (elements) => {
   // Flattens a nested array (the nesting can be to any depth).
   // Example: flatten([1, [2], [3, [[4]]]]); => [1, 2, 3, 4];
+  each(elements, (element) => {
+    if (Array.isArray(element)) {
+      elements = flatten([].concat([], ...elements));
+    }
+  });
+
+  return elements;
 };
 
 /* eslint-enable no-unused-vars, max-len */

src/class.js

@@ -1,26 +1,66 @@
-// Create a class called User.
+// Part 1
+// Create a class called User using the ES6 class keyword.
 // The constructor of the class should have a parameter called `options`.
 // `options` will be an object that will have the properties `email` and `password`.
 // Set the `email` and `password` properties on the class.
 // Add a method called `comparePasswords`.  `comparePasswords` should have a parameter
 // for a potential password that will be compared to the `password` property.
 // Return true if the potential password matches the `password` property.  Otherwise return false.
 
+// code here
 
-/* eslint-disable no-undef */ // Remove this comment once you write your classes.
+class User {
+  constructor(options) {
+    this.email = options.email;
+    this.password = options.password;
+  }
 
+  comparePasswords(somePassword) {
+    return somePassword === this.password;
+  }
+}
 
-// Create a class called `Animal` and a class called `Cat`.
+// Part 2
+// Create a class called `Animal` and a class called `Cat` using ES6 classes.
 // `Cat` should extend the `Animal` class.
 // Animal and Cat should both have a parameter called `options` in their constructors.
 // Animal should have the property `age` that's set in the constructor and the method
-// `growOlder` that returns the age.
+// `growOlder` that returns the age after incrementing it.
 // Cat should have the property `name` that is set in the constructor and the method
 // `meow` that should return the string `<name> meowed!` where `<name>` is the `name`
 // property set on the Cat instance.
 
+// code here
+
+/* eslint-disable no-undef */
+
+class Animal {
+  constructor(options, age) {
+    this.options = options;
+    this.age = options.age;
+  }
+
+  growOlder() {
+    this.age = this.age + 1;
+    return this.age;
+  }
+}
+
+class Cat extends Animal {
+  constructor(options, name, age) {
+    super(options, name, age);
+    this.options = options;
+    this.name = options.name;
+    this.age = options.age;
+  }
+
+  meow() {
+    return `${this.name} meowed!`;
+  }
+}
 
 module.exports = {
   User,
-  Cat
+  Cat,
+  Animal,
 };

src/closure.js

@@ -5,27 +5,88 @@ const counter = () => {
   // Example: const newCounter = counter();
   // newCounter(); // 1
   // newCounter(); // 2
+  let count = 0;
+  return () => {
+    ++count;
+    return count;
+  };
 };
 
 const counterFactory = () => {
   // Return an object that has two methods called `increment` and `decrement`.
   // `increment` should increment a counter variable in closure scope and return it.
   // `decrement` should decrement the counter variable and return it.
+  let s = 0;
+  return {
+    increment: () => {
+      s += 1;
+      return s;
+    },
+    decrement: () => {
+      s -= 1;
+      return s;
+    },
+  };
 };
 
 const limitFunctionCallCount = (cb, n) => {
   // Should return a function that invokes `cb`.
   // The returned function should only allow `cb` to be invoked `n` times.
+  let count = 0;
+
+  return (...args) => {
+    if (n === count) {
+      return null;
+    }
+
+    count++;
+    return cb(...args);
+  };
 };
 
-/* Extra Credit */
+/* STRETCH PROBLEM */
+
 const cacheFunction = (cb) => {
   // Should return a funciton that invokes `cb`.
   // A cache (object) should be kept in closure scope.
   // The cache should keep track of all arguments have been used to invoke this function.
   // If the returned function is invoked with arguments that it has already seen
   // then it should return the cached result and not invoke `cb` again.
   // `cb` should only ever be invoked once for a given set of arguments.
+  const storage = {};
+  const args = [];
+  const tempCB = cb;
+  let tempFunc = tempCB.toString().split(' ')[1];
+  if (tempCB !== undefined) {
+    const ourFunc = tempCB.toString().split(' ')[1].split('');
+
+    for (let i = 0; i <= ourFunc.indexOf('(') + 1; i++) {
+      ourFunc.splice(ourFunc[i], 1);
+    }
+
+    tempFunc = ourFunc;
+    tempFunc.shift();
+    tempFunc.pop();
+
+    console.log('OUR NEW FUNC SHOUDL BE: ', tempFunc);
+  }
+
+  console.log(tempFunc[0]);
+
+  if (storage[tempFunc[0]] === undefined) {
+    storage[tempFunc[0]] = cb();
+  }
+
+  console.log('RES IS: ', cb(tempFunc[0]));
+
+  return function () {
+    const arg = tempFunc[0];
+    if (!storage[arg]) {
+      storage[arg] = cb(arg);
+    }
+
+    return storage[arg];
+  };
 };
 
 /* eslint-enable no-unused-vars */
@@ -34,5 +95,5 @@ module.exports = {
   counter,
   counterFactory,
   cacheFunction,
-  limitFunctionCallCount
+  limitFunctionCallCount,
 };

src/es6.js

@@ -7,50 +7,47 @@
 //----------------
 // const, =>, default parameters, arrow functions default return statements using ()
 
-var food = 'pineapple';
+let food = `pineapple`;
 
-var isMyFavoriteFood = function(food) {
-  food = food || 'thousand-year-old egg'; //This sets a default value if `food` is falsey
-  return food === 'thousand-year-old egg';
+const isMyFavoriteFood = (food) => {
+  food = food || `thousand-year-old egg`; //This sets a default value if `food` is falsey
+  return food === `thousand-year-old egg`;
 };
 
-var isThisMyFavorite = isMyFavoriteFood(food);
+let isThisMyFavorite = isMyFavoriteFood(food);
 
 //----------------
 //const, class, template literals, enhanced object literals (foo: foo, -> foo,)
 
-var User = function(options) {
+const User = (options) => {
   this.username = options.username;
   this.password = options.password;
-  this.sayHi = function() {
-    return this.username + ' says hello!';
+  this.sayHi = () => {
+    return `${this.username} says hello!`;
   };
 }
 
-var username = 'JavaScriptForever';
-var password = 'password';
+let username = `JavaScriptForever`;
+let password = `password`;
 
-var me = new User({
-  username: username,
-  password: password,
-});
+let me = new User({ username, password });
 
 // ----------------
 // let, const, =>, ... (spread operator)
 
-var addArgs = function () {
-  var sum = 0;
-  for (var i = 0; i < arguments.length; i++) {
+const addArgs = () => {
+  let sum = 0;
+  for (let i = 0; i < arguments.length; i++) {
     sum += arguments[i];
   }
   return sum;
 };
 
-var argsToCb = function (cb) {
-  var args = Array.prototype.slice.call(arguments);
-  return cb.apply(null, args.splice(1));
+const argsToCb = (cb) => {
+  const args = Array.prototype.slice.call(arguments);
+  return cb(...args.splice(1));
 };
 
-var result = argsToCb(addArgs, 1, 2, 3, 4, 5); //result should be 15
+let result = argsToCb(addArgs, 1, 2, 3, 4, 5); //result should be 15
 
 /* eslint-enable */